This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the
pathway.
If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Summary:
Xylan is found in the cell walls of plants and some green and red algae, and is the major constituent of hemicellulose. The most common type of xylan is by far a (1→4)-β-D-xylan, a linear polymer of β-D-xylopyranose residues linked by (1→4) glycosidic bonds. This polysaccharide backbone is often decorated by additional sugars, forming complex polymers such as arabinoxylan and glucuronoxylan.

Arabinoxylans have been identified in wheat, rye, barley, oat, rice, and sorghum, as well as in some less common plants, including pangola grass, bamboo shoots and rye grass. Glucuronoxylans and glucuronoarabinoxylans are located mainly in the secondary wall and function as an adhesive by forming covalent and non-covalent bonds with lignin, cellulose, and other polymers essential to the integrity of the cell wall.

Angiosperm (hardwood) glucuronoxylans also have a high rate of substitution (70-80%) by acetyl groups, at position 2 and/or 3 of the β-D-xylopyranosyl. The degradation of cell wall is immensely important in industrial production as a supplement in animal feed, food and beverages, textiles, bleaching and production of biofuels. The main enzymes involved in xylan degradation are the xylanases. These enzymes are produced mainly by microorganisms that break down plant cell walls, but are also present in marine algae, protozoans, crustaceans, insects, snails and seeds of land plants [Sunna97].